Titanium pipe fittings are treated to remove residues

When the hydrogen content in titanium pipe fittings is too high, it will cause a sharp decline in impact toughness and notch tensile strength due to brittleness. Therefore, it is generally stipulated that the hydrogen content in titanium pipes should not exceed 0.015%. To reduce hydrogen absorption, fingerprints, rolling mill marks, grease and other residues should be removed from the parts before heat treatment, and there should be no water vapor in the heat treatment furnace. If the hydrogen content of titanium pipe fittings exceeds the allowable value, it must be removed by vacuum annealing.

When the temperature does not exceed 540 degrees, the oxide film on titanium pipe fittings will not thicken significantly. However, at higher heat treatment temperatures, the oxidation rate will accelerate rapidly, and at the same time, a layer of contamination will diffuse inside the oxidized material. The oxygen-contaminated layer has a high brittleness ratio, causing cracks and damage on the surface of parts. The deoxygenated contaminated layer can be treated by mechanical processing methods or chemical methods such as pickling and chemical milling. During heat treatment, the heating time should be shortened as much as possible while ensuring the heat treatment. It can also be carried out in a vacuum furnace or an inert gas heating furnace. Pollution caused by the heating of titanium pipe fittings in an air furnace should be appropriately avoided or reduced.